What do different "builds," same model have in common
Take the model number of a Dell desktop computer. For example, Dell Optiplex 7010. What defines the model number? I am pretty certain that a model number offers "customizations" for the processor, memory, maybe graphics card. It seems like there are multiple motherboards available, too. I base that on the fact that there is more than one form factor attached to a motherboard.
Maybe what ties all of the variations together is the chipset?